U.S. patent application number 12/691897 was filed with the patent office on 2010-07-29 for recording apparatus and method of controlling air releasing valve in drying section of the recording apparatus.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Keiji HARA, Osamu SHINKAWA.
Application Number | 20100188455 12/691897 |
Document ID | / |
Family ID | 42353843 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100188455 |
Kind Code |
A1 |
SHINKAWA; Osamu ; et
al. |
July 29, 2010 |
RECORDING APPARATUS AND METHOD OF CONTROLLING AIR RELEASING VALVE
IN DRYING SECTION OF THE RECORDING APPARATUS
Abstract
Provided is a recording apparatus comprising recording heads; a
medium feeding unit; a position detecting unit; a drying section
including an air generating unit and generates air, an air guiding
portion, the drying section bringing the air guided by the air
guiding portion into contact with the recording medium via an
opening portion; a branching path which branches off over the range
where the opening portion extends in the feeding direction,
branches and guides part of the air flowing from the upstream side
to the downstream side in the feeding direction in the air guiding
portion of the drying section; an air releasing valve; and a
control section which controls the opening or closing of the air
releasing valve according to the position of the recording
medium.
Inventors: |
SHINKAWA; Osamu; (Chino-shi,
JP) ; HARA; Keiji; (Minowa-machi, JP) |
Correspondence
Address: |
Workman Nydegger;1000 Eagle Gate Tower
60 East South Temple
Salt Lake City
UT
84111
US
|
Assignee: |
SEIKO EPSON CORPORATION
Tokyo
JP
|
Family ID: |
42353843 |
Appl. No.: |
12/691897 |
Filed: |
January 22, 2010 |
Current U.S.
Class: |
347/16 ;
347/102 |
Current CPC
Class: |
B41J 29/377 20130101;
B41J 2/155 20130101; B41J 11/002 20130101 |
Class at
Publication: |
347/16 ;
347/102 |
International
Class: |
B41J 29/38 20060101
B41J029/38; B41J 2/01 20060101 B41J002/01 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2009 |
JP |
2009-013986 |
Claims
1. A recording apparatus comprising: recording heads that execute
recording by discharging ink onto a recording medium; a medium
feeding unit that feeds the recording medium to a downstream side
in a feeding direction; a position detecting unit that detects the
position of the recording medium in the feeding direction; a drying
section including an air generating unit that is provided on the
downstream side of the recording heads in the feeding direction and
generates air, an air guiding portion that guides the air generated
by the air generating unit from the upstream side to the downstream
side in the feeding direction and forms a flow passage, and an
opening portion which extends in the feeding direction in the
middle of the flow passage of the air guiding portion so as to face
the recording medium, the drying section bringing the air guided by
the air guiding portion into contact with the recording medium via
the opening portion so as to dry the ink on the recording medium; a
branching path which branches off over the range where the opening
portion extends in the feeding direction, branches and guides part
of the air flowing from the upstream side to the downstream side in
the feeding direction in the air guiding portion of the drying
section; an air releasing valve which is provided on the branching
path and is opened or closed; and a control section which controls
the opening or closing of the air releasing valve according to the
position of the recording medium.
2. The recording apparatus according to claim 1, wherein, in the
case where the recording medium passes through the drying section,
the control section closes the air releasing valve until the
tailing end of the recording medium reaches the position of a
branching point on which the branching path branches from the air
guiding portion in the feeding direction, the control section opens
the air releasing valve when the tailing end of the recording
medium reaches the position of the branching point in the feeding
direction, and the control section closes the air releasing valve
when the tailing end of the recording medium reaches the position
of the downstream end of the opening portion in the feeding
direction.
3. The recording apparatus according to claim 1, wherein the air
guiding portion in the drying section has an air flow passage of
which a sectional area gradually decreases as the air advances from
the upstream side to the downstream side in the range where the
opening portion extends in the feeding direction.
4. The recording apparatus according to claim 1, wherein a
plurality of the branching paths having the air releasing valve is
provided; wherein a plurality of the branching points is arranged
in series in the feeding direction, on which the branching paths
branch off from the air guiding portion; wherein, with respect to
the air releasing valves other than the air releasing valve
corresponding to the furthest downstream branching point in the
feeding direction among the plurality of the air releasing valves,
when the tailing end of the recording medium reaches the position
of one branching point in the feeding direction, the control
section opens the air releasing valve corresponding to the one
branching point, and when the tailing end of the recording medium
reaches the position of another branching point adjacent to the
downstream side of the one branching point in the feeding
direction, the control section opens the air releasing valve
corresponding to the another branching point and closes the air
releasing valve corresponding to the one branching point; and
wherein, with respect to the air releasing valve corresponding to
the furthest downstream branching point in the feeding direction
among the plurality of the air releasing valves, when the tailing
end of the recording medium reaches the position of the furthest
downstream branching point the feeding direction, the control
section opens the air releasing valve corresponding to the furthest
downstream branching point in the feeding direction, and when the
tailing end of the recording medium reaches the position of the
downstream end of the opening porting in the feeding direction, the
control section closes the air releasing valve corresponding to the
furthest downstream branching point in the feeding direction.
5. The recording apparatus according to claim 1, wherein, when the
number of the branching paths is one, the distance between the
tailing end of the preceding recording medium and the leading end
of the succeeding recording medium is equal to the distance from
the branching point of the branching path in the feeding direction
to the downstream end of the opening portion in the feeding
direction; and wherein, when the number of the branching paths is
more than one, the distance between the tailing end of the
preceding recording medium and the leading end of the succeeding
recording medium is equal to the distance from the furthest
downstream branching point in the feeding direction to the
downstream end of the opening portion in the feeding direction.
6. A method of controlling an air releasing valve in a drying
section of a recording apparatus, comprising: feeding a recording
medium to a downstream side in a feeding direction by a medium
feeding unit; recording by discharging ink onto the recording
medium from recording heads; detecting a position of the recording
medium in the feeding direction by a position detecting unit;
drying ink on the recording medium using a drying section by
bringing the air guided by the air guiding portion into contact
with the recording medium via an opening portion, the drying
section including an air generating unit that is provided on the
downstream side of the recording heads in the feeding direction and
generates air, an air guiding portion that guides the air generated
by the air generating unit from the upstream side to the downstream
side in the feeding direction and forms a flow passage, and an
opening portion that extends in the feeding direction in the middle
of the flow passage of the air guiding portion so as to face the
recording medium; opening an air releasing valve provided on a
branching path when the tailing end of a recording medium in the
feeding direction reaches a position of a branching point where the
branching path, which branches off over the range where the opening
portion extends in the feeding direction, branches and guides part
of the air flowing from the upstream side to the downstream side in
the feeding direction in the air guiding portion of the drying
section, branches off from the air guiding portion; and closing the
air releasing valve when the tailing end of the recording medium
reaches the position of the downstream end of the opening portion
in the feeding direction after the opening of the air releasing
valve.
7. A method of controlling a plurality of air releasing valves in a
drying section of a recording apparatus, comprising: feeding a
recording medium to a downstream side in a feeding direction by a
medium feeding unit; recording by discharging ink onto the
recording medium from recording heads; detecting a position of the
recording medium in the feeding direction by a position detecting
unit; drying ink on the recording medium using a drying section by
bringing the air guided by the air guiding portion into contact
with the recording medium via an opening portion, the drying
section including an air generating unit that is provided on the
downstream side of the recording heads in the feeding direction and
generates air, an air guiding portion that guides the air generated
by the air generating unit from the upstream side to the downstream
side in the feeding direction and forms a flow passage, and an
opening portion that extends in the feeding direction in the middle
of the flow passage of the air guiding portion so as to face the
recording medium; with respect to a plurality of air releasing
valves that are arranged in series in this order in the feeding
direction, branched off over the range where the opening portion
extends in the feeding direction and provided on a plurality of
branching paths that branches and guides part of the air flowing
from the upstream side to the downstream side in the feeding
direction in the air guiding portion of the drying section, opening
an air releasing valve corresponding to one branching point when
the tailing end of the recording medium reaches the position of the
one branching point in the feeding direction, with respect to the
air releasing valves other than the air releasing valve
corresponding to the furthest downstream branching point in the
feeding direction among a plurality of branching points on which
the plurality of the branching paths branches off from the air
guiding portion among the plurality of the air releasing valves,
and opening the air releasing valve corresponding to the furthest
downstream branching point in the feeding direction when the
tailing end of the recording medium reaches the position of the
furthest downstream branching point in the feeding direction, with
respect to the air releasing valve corresponding to the furthest
downstream branching point in the feeding direction among the
plurality of the air releasing valves; and closing an air releasing
valve corresponding to one branching point when the tailing end of
the recording medium reaches a position of another branching point
adjacent to the downstream side of the one branching point in the
feeding direction, with respect to the air releasing valves other
than the air releasing valve corresponding to the furthest
downstream branching point in the feeding direction among the
plurality of the air releasing valves, and closing the air
releasing valve corresponding to the furthest downstream branching
point in the feeding direction when the tailing end of the
recording medium reaches the position of the downstream end of the
opening portion in the feeding direction, with respect to the air
releasing valve corresponding to the furthest downstream branching
point in the feeding direction among the plurality of the air
releasing valves.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention relates to a recording apparatus
including recording heads which execute recording by discharging
ink onto a recording medium; a medium feeding unit which feeds the
recording medium to a downstream side in the feeding direction; and
a drying section including an air generating unit which is provided
on the downstream side of the recording heads in the feeding
direction and generates air, an air guiding portion which guides
the air generated by the air generating unit from the upstream side
to the downstream side in the feeding direction and forms a flow
passage, and an opening portion which extends in the feeding
direction in the middle of the flow passage in the air guiding
portion so as to face the recording medium, the drying section
bringing the air guided by the air guiding portion into contact
with the recording medium via the opening portion and drying ink on
the recording medium, and a method of controlling the drying
section in the recording apparatus. In the present application, the
recording apparatus includes such machines as an ink jet printer, a
wire dot printer, a laser printer, a line printer, a copying
machine, a facsimile, and the like.
[0003] 2. Related Art
[0004] In the related art, according to JP-A-2002-292841, the
recording apparatus includes recording heads and a drying unit.
Among these, the recording heads were provided so as to execute
recording by discharging ink onto a sheet which is an example of a
recording medium. Furthermore, the drying unit was provided so as
to blow hot air onto the recorded sheet. Thus, the drying of ink on
the recorded sheet can be prompted.
[0005] However, the amount of the hot air blown onto the sheet was
always constant. Moreover, when the hot air which includes factors
spanning from an upstream side to a downstream side in a sheet
feeding direction is blown onto a sheet, in other words, if the hot
air is obliquely blown onto the surface of the sheet from the
tailing end side to the leading end side of the sheet, there is
problem that the hot air may go into the gap between the tailing
end of the sheet and a supporting portion which supports the sheet
when the tailing end of the sheet passes through the drying unit.
In this case, there is a problem in that the tailing end of the
sheet flutters because the tailing end is separated from the
supporting portion and receives the hot air. In addition, the
fluttering causes the problem of so called paper jamming.
SUMMARY
[0006] An advantage of some aspects of the invention is that it
provides a recording apparatus which reduces fluttering of the
tailing end of a recording medium in a feeding direction caused by
air when drying ink on the recording medium with the air generated
therein, and a method of controlling a drying section in the
recording apparatus.
[0007] According to a first aspect of the invention, the recording
apparatus includes recording heads that execute recording by
discharging ink onto a recording medium; a medium feeding unit that
feeds the recording medium to a downstream side in a feeding
direction; a position detecting unit that detects the position of
the recording medium in the feeding direction; a drying section
including an air generating unit that is provided on the downstream
side of the recording heads in the feeding direction and generates
air, an air guiding portion that guides the air generated by the
air generating unit from the upstream side to the downstream side
in the feeding direction and forms a flow passage, and an opening
portion which extends in the feeding direction in the middle of the
flow passage of the air guiding portion so as to face the recording
medium, the drying section bringing the air guided by the air
guiding portion into contact with the recording medium via the
opening portion so as to dry the ink on the recording medium; a
branching path which branches off over the range where the opening
portion extends in the feeding direction, branches and guides part
of the air flowing from the upstream side to the downstream side in
the feeding direction in the air guiding portion of the drying
section; an air releasing valve which is provided on the branching
path and is opened or closed; and a control section which controls
the opening or closing of the air releasing valve according to the
position of the recording medium.
[0008] According to the above-described aspect, the recording
apparatus is provided with the branching path, the air releasing
valve, and the control section. Accordingly, it is possible to
reduce the flow amount and rate of the air that comes into contact
with a recording medium by switching the state of the air releasing
valve from a closed state to an opened state. In other words, it is
possible to adjust the flow amount and rate of the air that comes
into contact with the recording medium in the downstream side of a
branching point on which the branching path branches off from the
air guiding portion in the feeding direction without changing the
output of the air generating unit. As a result, it is possible to
reduce the problem of the tailing end of the recording medium
fluttering.
[0009] For example, the control section controls the air releasing
valve to be in an opened state from when the tailing end of the
recording medium passes the branching point of the branching path
to when the tailing end of the recording medium passes the
downstream end of the opening portion in the feeding direction. In
this case, it is possible to branch off part of the air to the
branching path. Accordingly, it is possible to reduce the flow
amount of the air that comes into contact with the tailing end of
the recording medium via the opening portion. In addition, it is
possible to lower the flow rate of the air that comes into contact
with the tailing end of the recording medium via the opening
portion by branching off part of the air. As a result, it is
possible to reduce the problem of the tailing end of the recording
medium fluttering. In other words, it is possible to lessen the
problem that the tailing end of the recording medium flaps.
[0010] As a second aspect of the invention according to the
above-described aspect, in the case where the recording medium
passes through the drying section, the control section closes the
air releasing valve until the tailing end of the recording medium
reaches the position of a branching point on which the branching
path branches off from the air guiding portion in the feeding
direction. Furthermore, the control section opens the air releasing
valve when the tailing end of the recording medium reaches the
position of the branching point in the feeding direction, and the
control section closes the air releasing valve when the tailing end
of the recording medium reaches the position of the downstream end
of the opening portion in the feeding direction.
[0011] Here, the "branching point" refers to a spot where a path is
divided. Precisely, it refers to a spot where a path starts to be
divided.
[0012] According to the second aspect of the invention, in addition
to the same action and effect as in the first aspect, part of the
air can be branched off to the branching path when the tailing end
of the recording medium reaches the position of the branching point
in the feeding direction as described above. Accordingly, it is
possible to reduce the flow amount of the air that comes into
contact with the tailing end of the recording medium via the
opening portion. Furthermore, it is possible to lower the flow rate
of the air that comes into contact with the tailing end of the
recording medium via the opening portion by branching off part of
the air.
[0013] Moreover, the air releasing valve is configured to be closed
when the tailing end of the recording medium reaches the position
of the downstream end of the opening portion in the feeding
direction. Accordingly, it is possible to dry ink on the recording
medium by returning the level of the flow amount and flow rate of
the air that comes into contact with the leading end side of the
succeeding recording medium back to the initial level. In other
words, it is possible to maintain the drying efficiency for the
leading end side of the recording medium such that there is no
problem of it fluttering due to increasing the flow amount and flow
rate of the air.
[0014] As a third aspect of the invention according to the first
aspect, the air guiding portion in the drying section has an air
flow passage of which the sectional areas gradually decreases as
the air advances from the upstream side to the downstream side in
the flowing direction within the range where the opening portion
extends in the feeding direction.
[0015] According to the above-described aspect, in addition to the
same action and effect as in the first aspect, it is possible to
raise the flow rate of the air in the downstream side so as to be
higher than the flow rate in the upstream side by lowering the flow
rate of the air in the upstream side in the flowing direction.
[0016] Accordingly it is possible to increase the viscosity of the
ink on the recording medium by bringing the slow-flowing air in the
upstream side in the feeding direction into contact with the
recording medium. In other words, it is possible to reduce the
problem that half-dried ink is disturbed by the air.
[0017] Then, it is possible to dry the ink completely by bringing
fast-flowing air into contact with the high-viscosity ink on the
recording medium in the downstream side in the feeding
direction.
[0018] Furthermore, when the flow rate of the air that comes into
contact with the recording medium gets higher as it advances in the
downstream side in the feeding direction, the problem is raised
that the tailing end of the recording medium flutters. In this
case, the branching path and the air releasing valve are
particularly useful.
[0019] With the above-described configuration of sectional areas,
it is possible to make the flow rate of the air that comes into
contact with the recording medium in the upstream side of the
branching point in the feeding direction lower than the flow rate
of the air in the downstream side in a state where the air
releasing valve is closed. Therefore, it is possible to eliminate
the problem of the tailing end of the recording medium fluttering
in the upstream side of the branching point.
[0020] As a fourth aspect of the invention according to the first
aspect, a plurality of the branching paths having the air releasing
valves is provided, and a plurality of the branching points is
arranged in series in the feeding direction, on which the branching
paths branch off from the air guiding portion. With respect to the
air releasing valves other than the air releasing valve
corresponding to the furthest downstream branching point in the
feeding direction among the plurality of the air releasing valves,
when the tailing end of the recording medium reaches the position
of one branching point in the feeding direction, the control
section opens the air releasing valve corresponding to the one
branching point, and when the tailing end of the recording medium
reaches the position of another branching point adjacent to the
downstream side of one branching point in the feeding direction,
the control section opens the air releasing valve corresponding to
the another branching point and closes the air releasing valve
corresponding to the one branching point. With respect to the air
releasing valve corresponding to the furthest downstream branching
point in the feeding direction among the plurality of the air
releasing valves, when the tailing end of the recording medium
reaches the position of the furthest downstream branching point in
the feeding direction, the control section opens the air releasing
valve corresponding to the furthest downstream branching point in
the feeding direction, and when the tailing end of the recording
medium reaches the position of the downstream end of the opening
porting in the feeding direction, the control section closes the
air releasing valve corresponding to the furthest downstream
branching point in the feeding direction.
[0021] According to the fourth aspect of the invention, in addition
to the same action and effect as in the first aspect, the control
section opens air releasing valve corresponding to the branching
point from among the plurality of the air releasing valves
according to the position of the tailing end of the recording
medium. Accordingly, it is possible to lower the flow rate of the
air that comes into contact with the tailing end of the recording
medium. Specifically, it is useful when the opening portion of the
drying section is long in the feeding direction.
[0022] As a fifth aspect of the invention according to the first
aspect, when the number of branching paths is one, the distance
between the tailing end of the preceding recording medium and the
leading end of the succeeding recording medium is equal to the
distance from the branching point of the branching path in the
feeding direction to the downstream end of the opening portion in
the feeding direction. When the number of branching paths is more
than one, the distance between the tailing end of the preceding
recording medium and the leading end of the succeeding recording
medium is equal to the distance from the furthest downstream
branching point in the feeding direction to the downstream end of
the opening portion in the feeding direction.
[0023] Here, the "equal" preferably refers to "substantially the
same," and allows a slight variance in the position of the
recording medium.
[0024] According to the fifth aspect of the invention, in addition
to the same action and effect as in the first aspect, there is no
problem due to the change in the flow amount of the air for the
tailing end of the preceding recording medium affects the
succeeding recording medium. In other words, there is no problem
due to a fall in the drying efficiency of the ink affecting the
succeeding recording medium even when the air releasing valve is
opened or closed in order to adjust the flow amount of the air for
the tailing end of the preceding recording medium.
[0025] As a sixth aspect of the invention, a method of controlling
an air releasing valve in a drying section of a recording apparatus
includes feeding a recording medium to a downstream side in a
feeding direction by a medium feeding unit; recording by
discharging ink onto the recording medium from recording heads;
detecting a position of the recording medium in the feeding
direction by a position detecting unit; drying ink on the recording
medium using the drying section by bringing the air guided by the
air guiding portion into contact with the recording medium via an
opening portion, the drying section including an air generating
unit that is provided on the downstream side of the recording heads
in the feeding direction and generates air, an air guiding portion
that guides the air generated by the air generating unit from the
upstream side to the downstream side in the feeding direction and
forms a flow passage, and an opening portion that extends in the
feeding direction in the middle of the flow passage of the air
guiding portion so as to face the recording medium; opening an air
releasing valve provided on a branching path when the tailing end
of a recording medium in the feeding direction reaches a position
of the branching point where the branching path, which branches off
over the range where the opening portion extends in the feeding
direction, branches and guides part of the air flowing from the
upstream side to the downstream side in the feeding direction in
the air guiding portion of the drying section, branches off from
the air guiding portion; and closing the air releasing valve when
the tailing end of the recording medium reaches the position of the
downstream end of the opening portion in the feeding direction
after the opening of the air releasing valve.
[0026] According to the sixth aspect of the invention, it is
possible to obtain the same action and effect as in the second
aspect.
[0027] As a seventh aspect of the invention, a method of
controlling an air releasing valve in a drying section of a
recording apparatus includes feeding a recording medium to a
downstream side in a feeding direction by a medium feeding unit;
recording by discharging ink onto the recording medium from
recording heads; detecting a position of the recording medium in
the feeding direction by a position detecting unit; drying ink on
the recording medium using a drying section by bringing the air
guided by the air guiding portion into contact with the recording
medium via an opening portion, the drying section including an air
generating unit that is provided on the downstream side of the
recording heads in the feeding direction and generates air, an air
guiding portion that guides the air generated by the air generating
unit from the upstream side to the downstream side in the feeding
direction and forms a flow passage, and an opening portion that
extends in the feeding direction in the middle of the flow passage
of the air guiding portion so as to face the recording medium; with
respect to a plurality of air releasing valves that are arranged in
series in this order in the feeding direction, branches off over
the range where the opening portion extends in the feeding
direction and provided on a plurality of branching paths that
branches and guides part of the air flowing from the upstream side
to the downstream side in the feeding direction in the air guiding
portion of the drying section, opening an air releasing valve
corresponding to one branching point when the tailing end of the
recording medium reaches the position of the one branching point in
the feeding direction, with respect to the air releasing valves
other than the air releasing valve corresponding to the furthest
downstream branching point in the feeding direction among a
plurality of branching points on which the plurality of the
branching paths branches off from the air guiding portion among the
plurality of the air releasing valves, and opening the air
releasing valve corresponding to the furthest downstream branching
point in the feeding direction when the tailing end of the
recording medium reaches the position of the furthest downstream
branching point in the feeding direction, with respect to the air
releasing valve corresponding to the furthest downstream branching
point in the feeding direction among the plurality of the air
releasing valves; and closing an air releasing valve corresponding
to one branching point when the tailing end of the recording medium
reaches a position of another branching point adjacent to the
downstream side of the one branching point in the feeding
direction, with respect to the air releasing valves other than the
air releasing valve corresponding to the furthest downstream
branching point in the feeding direction among the plurality of the
air releasing valves, and closing the air releasing valve
corresponding to the furthest downstream branching point in the
feeding direction when the tailing end of the recording medium
reaches the position of the downstream end of the opening portion
in the feeding direction, with respect to the air releasing valve
corresponding to furthest downstream the branching point in the
feeding direction among the plurality of the air releasing
valves.
[0028] According to the above aspect, it is possible to obtain the
same action and effect as in the fourth aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a side view schematically illustrating the whole
of a printer according to the invention.
[0030] FIG. 2 is a top view schematically illustrating the whole of
the printer according to the invention.
[0031] FIG. 3 is a side view schematically illustrating the
operation of a hot air unit according to the invention.
[0032] FIG. 4 is a side view schematically illustrating the
operation of the hot air unit according to the invention.
[0033] FIG. 5 is a side view schematically illustrating the
operation of the hot air unit according to the invention.
[0034] FIG. 6 is a flowchart showing the control of an air-opening
valve in the hot air unit according to the invention.
[0035] FIG. 7 is a side view schematically illustrating a hot air
unit according to the other embodiment 1.
[0036] FIG. 8 is a side view schematically illustrating the
operation of the hot air unit according to the other embodiment
2.
[0037] FIG. 9 is a side view schematically illustrating the
operation of the hot air unit according to the other embodiment
2.
[0038] FIG. 10 is a side view schematically illustrating the
operation of the hot air unit according to the other embodiment
2.
[0039] FIG. 11 is a side view schematically illustrating the
operation of the hot air unit according to the other embodiment
2.
[0040] FIG. 12 is a side view schematically illustrating the
operation of the hot air unit according to the other embodiment
2.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0041] Hereinafter, exemplary embodiments of the invention will be
explained with reference to accompanying drawings.
[0042] FIG. 1 is a side view schematically illustrating the whole
of an ink jet printer 1 (hereinafter referred to as "printer") as
an example of a "recording apparatus" or "liquid ejecting
apparatus" according to the invention. FIG. 2 is a top view
schematically illustrating the whole of the printer according to
the invention.
[0043] Here, the liquid ejecting apparatus is not limited to
recording apparatuses such as an ink jet type recording apparatus,
a copying machine and a facsimile which execute recording on a
recording member, such as a recording sheet, by ejecting ink from
recording heads as liquid ejecting heads onto the member. The
liquid ejecting apparatus also includes an apparatus which ejects
instead of ink a liquid for a specific application from liquid
ejecting heads corresponding to the above-described recording heads
onto a member to be ejected onto which corresponds to a member to
be recorded, so as to make the liquid adhere to the member to be
ejected onto.
[0044] Furthermore, in addition to the above-described recording
heads, the examples of the liquid ejecting heads include a coloring
material ejecting head used in manufacturing a color filter of a
liquid crystal display or the like, an electrode material
(conductive paste) ejecting head used in forming an electrode of an
organic EL display, a field emission display (FED) or the like, a
bio-organic ejecting head used in manufacturing a bio-chip, and a
sample ejecting head ejecting a sample as a precision pipette.
[0045] As shown in FIG. 1 and FIG. 2, the printer 1 is provided
with a transport unit 10, a recording section 40, a drying section
50, a position detecting unit 30, and a control section 70. Among
these, the transport unit 10 is configured to transport a sheet P
to a downstream side in a feeding direction as a medium feeding
process. Specifically, the transport unit 10 includes a pair of
feeding rollers 11 provided on the upstream side of the recording
section 40 and a suction belt mechanism 20 provided on the
downstream side of the recording section 40 in the feeding
direction Y.
[0046] The pair of the feeding rollers 11 includes a driving
feeding roller 12 and a driven feeding roller 13. Among these, the
driving feeding roller 12 is configured to be driven by the force
of a first transport motor (not shown in the drawing). On the other
hand, the driven feeding roller 13 is configured to be rotated in
accordance with the rotation of the driving feeding roller 12. The
driving feeding roller 12 and the driven feeding roller 13 are
configured to transport the sheet P to the downstream side in the
feeding direction in tandem with each other.
[0047] The suction belt mechanism 20 is provided with three rollers
21a, 21b, and 21c, a belt 22 which have a plurality of holes and
are wound on the three rollers 21a, 21b, and 21c, and a suction
unit 24 which sucks air via the plurality of holes. A suction fan
may be used as the suction unit 24. The driving of the roller 21a
in the downstream side in the feeding direction by the force of a
second transport motor (not shown) causes the belt 22 to be driven
and feed the sheet P. A drying-time medium supporter 23 provided on
the upper side of the suction belt mechanism 20 is configured to
support the back side of the sheet P with the belt 22 interposed
therebetween.
[0048] The suction unit 24 is configured to suck air above the
drying-time medium supporter 23 downwardly via the plurality of
holes in the belt 22.
[0049] Furthermore, the suction unit is configured to suck the air
in the entire region of the drying-time medium supporter 23.
[0050] Accordingly, the suction unit 24 can firmly attach the sheet
P on the drying-time medium supporter 23 thereto with the belt 22
interposed therebetween. As a result, the sheet P can be fed to the
downstream side in the feeding direction with high precision by the
driving of the belt 22. In addition, the sheet P can be retained
when hot air is blown onto the sheet P by the drying section 50 to
be described later.
[0051] The recording section 40 is configured to execute recording
by discharging ink onto the surface of the sheet P fed by the pair
of the feeding rollers 11 in a recording process. Specifically, the
recording section 40 is provided with a recording-time medium
supporter 42, a plurality of recording heads 41, a plurality of
caps 43, and a windshield plate 44. Among these, the recording-time
medium supporter 42 is configured to support the back side of the
sheet P.
[0052] The plurality of the recording heads 41 is provided above
the recording-time medium supporter 42 so as to move in the width
direction X of the sheet P. Specifically, the heads are provided so
as to move between a recording position which faces the
recording-time medium supporter 42 and a waiting position which
does not face the recording-time medium supporter 42 by the driving
of a motor for moving heads (not shown) while being guided by a
first guiding portion (not shown).
[0053] The plurality of the caps 43 is provided in a position
facing the plurality of the recording heads 41 in a waiting
position so as to move in the facing direction Z. Specifically, the
caps are provided so as to move between a sealing position which
seals nozzle faces of the plurality of the recording heads 41 in
the waiting position and a retreating position which does not seal
the nozzle faces by the force of a motor for moving caps (not
shown) while being guided by a second guiding portion (not
shown).
[0054] The windshield plate 44 is provided on the downstream side
in the feeding direction of the plurality of the recording heads 41
in the recording position. Furthermore, the windshield plate 44 is
configured to reduce the advance of air generated in the drying
section 50 which will be described later to the recording section
40. In addition, the windshield plate 44 is configured to reduce
the conduction of heat generated in the drying section 50 to the
recording section 40.
[0055] It is preferable that the windshield plate 44 be formed of a
heat-insulating material which reduces the conduction of heat. In
addition, it is preferable that a plurality of windshield plate 44
be provided with slight gaps between one another.
[0056] The recording heads 41 are configured to execute recording
by discharging ink onto the surface of the sheet P.
[0057] The drying section 50 is configured to dry ink on the
recorded sheet P as a drying process. The drying section 50
includes a convection type hot air unit 51 which blows hot air onto
the sheet P and the drying-time medium supporter 23 described
above.
[0058] Here, the "convection type" refers to a method of
transmitting heat by fluid such as gas or liquid.
[0059] The hot air unit 51 includes an air inlet 52, an air outlet
53, and an air-opening valve 59b, which will be described later in
detail.
[0060] Among these, the air inlet 52 is provided so as to bring air
into the hot air unit 51. Furthermore, the air outlet 53 is
provided so as to release the air in the hot air unit 51 to the
outside. The air-opening valve 59b is provided on a branching path
59 which branches off from an air guiding portion 57 guiding air
from the air inlet 52 to the air outlet 53 (see FIG. 3 to FIG. 5).
In addition, the air-opening valve 59b is configured to be opened
or closed by the control section 70.
[0061] The position detecting unit 30 is configured to detect a
position of the sheet P in the feeding direction Y as a position
detecting process. Specifically, the position detecting unit 30
includes a first sheet detecting sensor 31 and a second sheet
detecting sensor 33.
[0062] Here, the first sheet detecting sensor 31 and the second
sheet detecting sensor 33 may be any one of a non-contact type
optical sensor or a contact type mechanical sensor. Any sensor may
be used if the sensor detects the leading end or the tailing end of
the sheet P so that the control section 70 can determine the
leading end or the tailing end of the sheet P.
[0063] A first encoder 32 is provided in the driving feeding roller
12. Accordingly, the control section 70 can determine the driving
amount of the driving feeding roller 12. The first sheet detecting
sensor 31 is provided in the vicinity of the driving feeding roller
12. As a result, the sheet P can be fed with high precision.
Specifically, recording is started when the sheet P is fed a
predetermined distance toward the downstream side after the first
sheet detecting sensor 31 detects the leading end of the sheet
P.
[0064] A second encoder 34 is provided in the roller 21b in the
upstream side. Accordingly, the control section 70 can determine
the driving amount of the suction belt mechanism 20. The second
sheet detecting sensor 33 is provided in the vicinity of the roller
21b in the upstream side. As a result, the sheet P can be fed in
the drying section 50 after recording with high precision.
Furthermore, the opening and closing of the air-opening valve 59b
can be switched with high precision in accordance with the position
of the tailing end of the sheet P as will be described below.
[0065] The sheet P dried by the drying section 50 is fed to the
downstream side so as to be discharge to a discharging section (not
shown).
[0066] Next, the hot air unit 51 of the drying section 50 will be
described in detail.
[0067] FIG. 3 to FIG. 5 are side views schematically illustrating
the operation of the hot air unit according to the invention. FIG.
6 is a flowchart showing the control of the air-opening valve in
the hot air unit according to the invention.
[0068] As shown in FIG. 3 to FIG. 5, the hot air unit 51 of the
drying section 50 in the invention is provided with an air inlet
52, an air outlet 53, an air generating unit 54, a heater 56, an
air guiding portion 57, an opening portion 58, a branching path 59
and an air-opening valve 59b.
[0069] Among these, the air inlet 52 is configured to bring air
into the hot air unit as described above. The air outlet 53 is
configured to release the air in the hot air unit to the outside as
described above.
[0070] Here, the air inlet 52 is provided on the upstream side in
the feeding direction, which is upward in the direction of the axis
Z of the hot air unit 51. On the other hand, the air outlet 53 is
provided on the downstream side in the feeding direction, which is
upward in the direction of the axis Z of the hot air unit 51.
[0071] The air generating unit 54 is configured to generate air to
flow from the air inlet 52 to the air outlet 53. In other words,
the air generating unit generates air to flow from the upstream
side to the downstream side in the feeding direction within the hot
air unit. Specifically, an example of the air generating unit 54 is
a blowing fan 55, which is so called a cross flow fan.
[0072] The "cross flow fan" is a fan of which the diameter is
relatively short and the length is transversely long. The cross
flow fan blows air drawn from one of the impellers in the radial
direction to the opposite impeller side in the radial direction.
The fan is also referred to as a transverse fan.
[0073] The blowing fan 55, which is a cross flow fan, extends in
the width direction X and matches with the shape of the air inlet
52 which is long in the width direction X.
[0074] The heater 56 is configured to heat the air blown by the
blowing fan 55. Accordingly, the air can be hot air. The heater 56
may be formed of a nichrome wire or the like, for example. The
nichrome wire can generate heat by itself due to electric
conduction and heat the nearby air.
[0075] The air guiding portion 57 is configured to guide the air
generated by the blowing fan 55 from the air inlet 52 to the air
outlet 53 within the hot air unit.
[0076] The opening portion 58 extends in the feeding direction Y so
as to face the sheet P below the direction of axis Z in the air
guiding portion 57. Specifically, the air flowing in the air
guiding portion 57 from the upstream side to the downstream side in
the feeding direction is blown onto the sheet P via the opening
portion 58. As shown in FIG. 3 to FIG. 5, the opening portion 58 is
provided in the vicinity of the drying-time medium supporter 23 and
faces therewith.
[0077] The branching path 59 branches off over the range where the
opening portion 58 extends in the feeding direction Y in the air
guiding portion 57. In addition, the branching path is provided so
as to branch and guide part of the air in the air guiding portion
57. In other words, if a flow passage 61 guided by the air guiding
portion 57 from the air inlet 52 to the air outlet 53 is assumed to
be the main line, part of the air is branched off and guided from
the main line. Here, a branching point 59a where the main line
branches off is within the range where the opening portion 58
extends in the feeding direction Y.
[0078] The air-opening valve 59b is provided on the branching path
59 so as to be switched to be opened and closed by the control
section 70. As an example of the air-opening valve 59b, a so-called
electromagnetic valve which is a solenoid valve can be used.
[0079] The air-opening valve 59b is formed to be long in the width
direction X in accordance with the shape of the section of the
branching path 59 (see FIG. 2).
[0080] When the air-opening valve 59b is opened, part of the air
guided to the branching path 59 is discharged from the hot air unit
51. On the other hand, when the air-opening valve 59b is closed,
part of the air guided in the branching path 59 stops flowing.
[0081] As a result, the flow amount and flow rate of the air in the
downstream side in the air flowing direction of the branching point
59a in the main line of the flow passage 61 may be changed.
[0082] Specifically, by opening the air-opening valve 59b, part of
the air flowing to the downstream side in the air flowing direction
of the branching point 59a in the main line of the flow passage 61
flows toward the branching path 59 and is discharged. Accordingly,
the amount of the air flowing to the downstream side in the air
flowing direction of the branching point 59a in the main line of
the flow passage 61 can be reduced by that much. The flow rate of
the air is lower than the flow rate when the air-opening valve 59b
is closed depending on the decrease of the air amount.
[0083] The sectional areas of the flow passage 61 in the air
guiding portion 57 become gradually smaller as the air advances to
the downstream side in the air flowing direction in the range where
the opening portion 58 extends in the feeding direction Y (see FIG.
3).
[0084] Here, when it is assumed that there are a first position, a
second position, and a third position in the downstream side of the
branching point 59a from the upstream side in the air flowing
direction in this order, the following relationship is
established;
Sectional area S1 of the first position>Sectional area S2 of the
second position>Sectional area S3 of the third position.
[0085] Due to the relationship above, the flow amount and flow rate
of the air can be gradually raised as the air advances to the
downstream side in the air flowing direction. Accordingly, the hot
air, which is relatively slowly flowing to the upstream side in the
feeding direction, comes into contact with the surface of the sheet
P in the range where the opening portion 58 extends, and evaporates
moisture in ink thereon so as to increase the viscosity of the ink.
In addition, as the viscosity of the ink on the surface of the
sheet P fed to the downstream side increases gradually, the blown
hot air becomes gradually intensified and evaporates organic
solvents in the ink components.
[0086] Here, it is assumed that the boiling point of the organic
solvents in the ink components is higher than that of moisture.
[0087] As a result, it is possible to dry the ink tidily with no
problem of the wet ink being disturbed by the air. In other words,
ink can be dried completely and efficiently by having hot air
blowing slowly from the upstream side so as to come into contact
with the ink on a sheet so as to increase the viscosity, and having
the hot air to strongly come into contact with the ink again
gradually as the air moves to the downstream side.
[0088] Next, the action and effect of the branching path 59 and the
air-opening valve 59b will be explained.
[0089] As shown in FIG. 3, the sheet P1 (P) is fed to the drying
section 50 from the recording section 40. At this point, the
air-opening valve 59b is in a closed state. In addition, the
leading end side of the sheet P1 is gradually fed to the downstream
side in the feeding direction, and faces the opening portion 58. At
this point, the leading end side of the sheet P1 is positioned in
the upstream side in the range where the opening portion 58
extends. Accordingly, as described above, the relatively slow hot
air comes into contact with the leading end side of the sheet P1.
Also, the moisture in the ink components on the leading end side of
the sheet P1 is evaporated so as to increase the viscosity of the
ink.
[0090] As shown in FIG. 4, the sheet P1 in the state shown in FIG.
3 is fed to the downstream side in the feeding direction. When the
leading end of the sheet P1 passes the branching point 59a and
reaches the third position (S3 (see FIG. 3)), the hot air blows
strongly. At this point, the viscosity of the ink has already
increased, and thus there is no problem of the ink being disturbed
by the air even when the air strongly blows. Moreover, the hot air
that blows strongly makes it possible to dry the ink
completely.
[0091] When the sheet P1 is fed to the downstream side in the
feeding direction and the tailing end P1b of the sheet P1 reaches
the position of the branching point 59a in the feeding direction Y,
the control section 70 opens the air-opening valve 59b.
Accordingly, it is possible to reduce the flow amount and flow rate
of the hot air in the vicinity of the first position in the
upstream side of the branching point 59a. As a result, it is
possible to reduce the problem that the tailing end P1b of the
sheet P1 flutters due to the hot air passing the third position (S3
(see FIG. 3)) of the main line in the flow passage 61 when the
sheet P1 is further fed to the downstream side in the feeding
direction, and the tailing end P1b of the sheet P1 is positioned
between the branching point 59a and the downstream end 58a of the
opening portion 58 in the feeding direction Y.
[0092] With simple explanation, at this point, the force that the
hot air goes into the gap between the tailing end Plb of the sheet
P1 and the belt 22 can be set to be weaker than the suction force
of the suction unit 24 of the suction belt mechanism 20.
[0093] As a result, there is no problem that the hot air flutters
the tailing end P1b of the sheet P1. In addition, there is no
problem that the surface of the sheet P1 is damaged. Also, there is
no problem of paper jamming.
[0094] In this case, the leading end P2a of the sheet P2 succeeding
the preceding sheet P1 is positioned in the upstream side within
the range where the opening portion 58 extends. Relatively slow hot
air comes into contact with the leading end side of the succeeding
sheet P2 as it does with the leading end Pla of the preceding sheet
P1. Then, the moisture in the ink components on the leading end
side of the succeeding sheet P2 is evaporated so as to increase the
viscosity of the ink. At this point, the succeeding sheet P2 is
positioned in the upstream side of the branching point 59a in the
feeding direction Y.
[0095] Accordingly, there is no influence from the opening of the
air-opening valve 59b. In other words, there is no problem in that
the drying efficiency is lowered.
[0096] As in the later description, the distance L1 from the
tailing end P1b of the preceding sheet P1 to the leading end of the
succeeding sheet is equal to the distance L2 (see FIG. 3) from the
branching point 59a in the feeding direction Y to the downstream
end 58a of the opening portion 58 in the feeding direction.
[0097] As shown in FIG. 5, the sheet in the state shown in FIG. 4
is fed further to the downstream side in the feeding direction.
When the tailing end P1b of the preceding sheet P1 reaches the
position of the downstream end 58a of the opening portion 58 in the
feeding direction Y, the control section 70 closes the air-opening
valve 59b. At this point, the leading end P2a of the succeeding
sheet P2 timely reaches the position of the branching point 59a in
the feeding direction Y. In other words, the distance L1 from the
tailing end P1b of the preceding sheet P1 to the leading end of the
succeeding sheet is equal to the distance L2 from the branching
point 59a in the feeding direction Y to the downstream end 58a of
the opening portion 58 in the feeding direction.
[0098] Accordingly, when the leading end side of the succeeding
sheet P2 passes the branching point 59a in the feeding direction Y,
the hot air strongly comes into contact with the leading end side
of the succeeding sheet P2. As a result, the ink can be dried
completely as in the leading end side of the preceding sheet P1.
Furthermore, when the tailing end P2b of the succeeding sheet P2
reaches the position of the branching point 59a in the feeding
direction Y, the control section 70 opens the air-opening valve
59b. Accordingly, as described above, it is possible to reduce the
flow amount and flow rate of the hot air in the vicinity of the
first position (S1 (see FIG. 3)) in the upstream side of the
branching point 59a. As a result, there is no problem that the hot
air flutters the tailing end P2b of the succeeding sheet P2 or the
tailing end P1b of the preceding sheet P1.
[0099] In the present embodiment, the number of branching points
59a is one and the position where the branching point 59a is
provided on the feeding direction Y is decided based on the
relationship between the force of the air, which goes into the gap
between the tailing end P1b of the sheet P1 and the belt 22 to
separate the sheet P1 from the belt 22, and the suction force of
the suction unit 24 in the suction belt mechanism 20. The sectional
areas of the flow passage 61 (S1 and S2) are relatively large and
the air can move slowly in the upstream side of the branching point
59a. Therefore, there is no problem that the hot air flutters the
tailing end P1b of the sheet P1.
[0100] On the other hand, there is a precondition that the
sectional area (S3) of the flow passage 61 is relatively small and
the air is strong enough such that the hot air flutters the tailing
end P1b of the sheet P1 in the downstream side of the branching
point 59a.
[0101] When the force of the air from the blowing fan 55 is
relatively weak, the suction unit 24 in the suction belt mechanism
20 is not always necessary. Only a pair of rollers such as the pair
of the feeding rollers may transport the sheet. In other words, the
hot air unit in the present embodiment may be combined with a
configuration where only the pair of the rollers transports the
sheet. In this case, it is needless to say that the relationship
between the tension or weight of the sheet and the force of the hot
air which goes into the back side of the sheet and separates the
sheet from the supporter which supports the sheet determines the
position of the branching point 59a.
[0102] In other words, it is needless to say that the position of
the branching point 59a in the feeding direction Y is determined
based on the relationship between the force with which the tailing
end P1b of the sheet P1 keeps its positioning at the position in
the direction of axis Z (such as suction force of the suction unit
in the suction belt mechanism, the tension and weight of the sheet,
and the like) and the force with which the air generating unit 54
(55) separates the tailing end P1b of the sheet P1 from the
supporters (22 and 23) which support the sheet P1, and the shape of
the air guiding portion 57.
[0103] Next, the operation above will be explained focusing on the
control section 70.
[0104] As shown in FIG. 6, in Step 11 (hereinafter, simply S11),
the control section 70 closes the air-opening valve 59b. At this
point, when the valve has already been closed, the state is
maintained. In additions, the process proceeds to S12 in order to
start transporting.
[0105] In S12, the sheet P1 is transported as a medium feeding
process. Specifically, the control section 70 drives the pair of
the feeding rollers 11 as transport unit 10 and feeds the sheet P1
to the downstream side in the feeding direction. Then, the process
proceeds to S13 in order to start recording.
[0106] Furthermore, it is assumed that the pair of the feeding
rollers 11 continues transporting the sheet P1 even after the
process proceeds to S13 and thereafter.
[0107] In S13, recording is executed as a recording process.
Specifically, the control section 70 transmits a signal to the
recording heads 41 of the recording section 40 to control the
recording heads 41 so as to discharge ink onto the sheet P1. Then,
the process proceeds to S14 in order to promote the drying of the
discharged ink.
[0108] In S14, the sheet P1 is transported to the hot air unit 51
which is the drying section 50 as a medium feeding process and a
drying process. Specifically, the control section 70 drives the
suction belt mechanism 20 as the transport unit 10 to feed the
sheet P1 to the hot air unit 51 in the downstream side in the
feeding direction. Then, the process proceeds to S15 in order to
determine the position of the tailing end P1b of the sheet P1.
[0109] Furthermore, it is assumed that the suction belt mechanism
20 continues transporting the sheet P1 even after the process
proceeds to S15 and thereafter.
[0110] In S15, it is determined whether the position of the tailing
end P1b of the sheet P1 is detected as a position detecting
process. Specifically, the control section 70 determines whether
the tailing end P1b of the sheet P1 fed by the suction belt
mechanism 20 passes the second sheet detecting sensor 33. Then,
when the tailing end P1b of the sheet P1 is detected, the process
proceeds to S16 in order to determine the current position of the
tailing end P1b of the sheet P1. On the other hand, when the
tailing end P1b of the sheet P1 is not detected, the sheet P1
continues to be transported until it is detected.
[0111] In S16, the measurement of the distance, from the tailing
end P1b of the sheet P1 being transported in the feeding direction
Y to the branching point 59a on which the branching path 59, where
the air-opening valve 59b is provided, branches off from the main
line, is started.
[0112] Specifically, at first, the control section 70 receives a
signal from the second sheet detecting sensor 33 that the tailing
end P1b of the sheet P1 has passed. Then, after the signal is
received, how much the suction belt mechanism 20 was driven is
calculated by the second encoder 34. Accordingly, the moving
distance of the sheet can be obtained after the tailing end P1b of
the sheet P1 has passed the second sheet detecting sensor 33. Then,
it is possible to obtain the distance from the tailing end of the
sheet P1 to the branching point 59a by calculating the difference
between the distance from the second sheet detecting sensor 33 to
the branching point 59a in the feeding direction Y and the moving
distance.
[0113] Then, the process proceeds to S17 in order to determine
whether to switch the opening and closing of the air-opening valve
59b.
[0114] In S17, the control section 70 determined whether it is the
point in time to open the air-opening valve 59b. Specifically, it
is determined whether the tailing end P1b of the sheet P1 reaches
the position of the branching point 59a in the feeding direction Y.
When it is determined the tailing end P1b of the sheet P1 reaches
the position, the process proceeds to S18 in order to reduce the
flow amount and flow rate of the air in the vicinity of the third
position (S3 (see FIG. 3)). On the other hand, when it is
determined that the tailing end P1b of the sheet P1 has not reached
the position, the process returns to S16.
[0115] In S18, the control section 70 opens the air-opening valve
59b as an air releasing valve opening process. Accordingly, as
described above, the flow amount and the flow rate of the hot air
can be reduced in the vicinity of the third position (S3 (see FIG.
3)) in the downstream side of the branching point 59a in the
feeding direction in the flow passage 61. As a result, there is no
problem that the hot air flutters the tailing end P1b of the sheet
P1. Then, the process proceeds to S19 in order to determine whether
there is a need to maintain the state of the reduced flow amount
and flow rate of the hot air.
[0116] In S19, it is determined whether the tailing end P1b of the
sheet P1 passes through the opening portion 58. To explain in
detail, it is determined whether the tailing end P1b of the sheet
P1 reaches the position of the downstream end 58a of the opening
portion 58 in the feeding direction Y. In other words, it is
determined whether the tailing end P1b of the sheet P1 reaches the
position where it does not face the opening portion 58.
Specifically, it is possible to determine the position of the
tailing end P1b of the sheet P1 by the second sheet detecting
sensor 33 and the second encoder 34 as described above. In
addition, it is determined whether the distance from the second
sheet detecting sensor 33 to the tailing end P1b of the sheet P1 is
close to the distance from the second sheet detecting sensor 33 to
the downstream end 58a of the opening portion 58 in the feeding
direction.
[0117] When it is determined that the tailing end P1b of the sheet
P1 reaches the position, the process proceeds to S20. This is for
returning to the initial state of the flow amount and flow rate of
the hot air without having to necessarily maintain the state of the
reduced flow amount and flow rate of the hot air in the vicinity of
the third position (S3 (see FIG. 3)).
[0118] On the other hand, when it is determined that the tailing
end P1b of the sheet P1 does not reach the position, the process
returns to S18. This is for maintaining the reduced flow amount and
flow rate of the hot air in the vicinity of the third position.
[0119] In S20, the control section 70 closes the air-opening valve
59b as an air releasing valve closing process. Accordingly, it is
possible to have the initial state of the flow amount and flow rate
of the hot air in the vicinity of the third position (S3 (see FIG.
3)). As a result, it is possible to dry the leading end of the
succeeding sheet P2 with efficiency. Then, the sequence is
ended.
[0120] As described above, it is preferable that the distance L1
from the tailing end P1b of the preceding sheet P1 to the leading
end P2a of the succeeding sheet P2 be equal to the distance L2 from
the position of the branching point 59a in the feeding direction Y
to the downstream end 58a of the opening portion 58 in the feeding
direction. This is because there is no problem such that the drying
efficiency in leading end side of the succeeding sheet P2
decreases.
[0121] As described above, by providing the air-opening valve 59b,
it is possible to reduce fluttering of the tailing end P1b of the
sheet P1 in the position within the range where the opening portion
58 extends in the feeding direction Y without adjusting the
intensity of the blowing fan 55. At the same time, it is possible
to maintain the drying efficiency of the leading end side of the
succeeding sheet P2. In other words, it is possible to reduce the
problem of the tailing end P1b of the preceding sheet P1 fluttering
without decreasing the drying efficiency of the leading end side of
the succeeding sheet P2.
[0122] In the present embodiment, the point in time to open the
air-opening valve 59b is set to the point in time when the tailing
end of the sheet reaches the branching point in the feeding
direction, but it is possible to set a point in time slightly
earlier than that. However, when it is too early, it is possible to
reduce the problem that the tailing end of the sheet flutters, but
there is a problem that the flow amount and flow rate of the hot
air to the leading end side of the sheet in the vicinity of the
third position (S3 (see FIG. 3)) reduces and drying is not
performed completely. Therefore, the point in time to open the
air-opening valve 59b may be advanced as long as the drying
efficiency in the leading end side of the sheet in the vicinity of
the third position (S3 (see FIG. 3)) does not decrease.
[0123] The printer 1 as a recording apparatus in the present
embodiment includes recording heads 41 which execute recording by
discharging ink onto the sheet P which is an example of the
recording medium, the transport unit 10 which feeds the sheet P to
the downstream side in the feeding direction as the medium feeding
unit, the second sheet detecting sensor 33 which detects the
position of the sheet P in the feeding direction Y as the position
detecting unit 30, the hot air unit 51 including the blowing fan 55
which is provided on the downstream side of the recording heads 41
in the feeding direction as an example of the air generating unit
54 generating air, the air guiding portion 57 which guides the air
generated by the blowing fan 55 from the upstream side to the
downstream side in the feeding direction and forms the flow passage
61, and the opening portion 58 which extends in the feeding
direction Y in the middle of the flow passage 61 of the air guiding
portion 57 so as to face the sheet P, the hot air unit 51 which
brings the air guided by the air guiding portion 57 into contact
with the sheet P via the opening portion 58 so as to dry ink
thereon as the drying section 50, the branching path 59 which
branches off over the range where the opening portion 58 extends in
the feeding direction Y, branches and guides part of the air
flowing from the upstream side to the downstream side in the
feeding direction in the air guiding portion 57 of the hot air unit
51, the air-opening valve 59b which is provided on the branching
path 59 and is opened and closed as an air releasing valve, and the
control section 70 which controls the opening and closing of the
air-opening valve 59b according to the position of the sheet P.
[0124] In the present embodiment, the control section 70 closes the
air-opening valve 59b until the tailing end P1b of the sheet P1
reaches the position of the branching point 59a on which the
branching path 59 branches from the air guiding portion 57 in the
feeding direction Y when the sheet P passes through the hot air
unit 51. The control section 70 opens the air-opening valve 59b
when the tailing end P1b of the sheet P1 reaches the position of
the branching point 59a in the feeding direction Y, and closes the
air-opening valve 59b when the tailing end P1b of the sheet P1
reaches the position of the downstream end 58a of the opening
portion 58 in the feeding direction Y.
[0125] In the present embodiment, the air guiding portion 57 in the
hot air unit 51 has sectional areas (S1 to S3) of the flow passage
61 of the air, which gradually decrease as the air advances from
the upstream side to the downstream side in the air flowing
direction within the range where the opening portion 58 extends in
the feeding direction Y.
[0126] In the present embodiment, when there are the first
position, the second position, and the third position from the
upstream side to the downstream side in the direction where the air
flows in this order (see FIG. 3), the following relationship is
established;
Sectional area S1 of the first position in the flow
passage>Sectional area S2 of the second position in the flow
passage>Sectional area S3 of the third position in the flow
passage.
[0127] Furthermore, in the present embodiment, the number of the
branching paths 59 is one and the distance L1 between the tailing
end P1b of the preceding sheet P1 and the leading end P2a of the
succeeding sheet P2 is equal to the distance L2 from the branching
point 59a of the branching path 59 in the feeding direction Y to
the downstream end 58a of the opening portion 58 in the feeding
direction.
[0128] The method of controlling the air-opening valve 59b in the
hot air unit 51 of the printer 1 according to the present
embodiment includes feeding the sheet P to the downstream side in
the feeding direction by the transport unit 10 (S12); recording by
discharging ink onto the sheet P from the recording heads 41 (S13);
detecting the position of the sheet P in the feeding direction Y by
the second sheet detection sensor 33 as the position detecting unit
30 (S15); drying the ink on the sheet using the hot air unit 51 by
bringing air guided by the air guiding portion 57 into contact with
the sheet P via the opening portion 58, the hot air unit 51
including the air generating unit 54 that is provided on the
downstream side of the recording heads 41 in the feeding direction
and generates air, the air guiding portion 57 that guides the air
generated by the air generating unit 54 from the upstream side to
the downstream side in the feeding direction and forms the flow
passage 61, and the opening portion 58 that extends in the feeding
direction Y in the middle of the flow passage 61 of the air guiding
portion 57 so as to face the sheet P (S14); opening the air-opening
valve 59b provided on the branching path 59 when the tailing end
P1b of the sheet P1 in the feeding direction Y reaches the position
of the branching point 59a on which the branching path 59, which
branches off over the range where the opening portion 58 extends in
the feeding direction Y, branches and guides part of the air
flowing from the upstream side to the downstream side in the
feeding direction in the air guiding portion 57 of the hot air unit
51, branches off from the air guiding portion 57 (S18); and closing
the air-opening valve 59b when the tailing end P1b of the sheet P1
reaches the position of the downstream end 58a of the opening
portion 58 in the feeding direction Y (S20) after opening the
air-opening valve 59b (S18).
Other embodiment 1
[0129] FIG. 7 is a side view schematically showing a hot air unit
according to other embodiment 1.
[0130] As shown in FIG. 7, the hot air unit 81 according to the
other embodiment 1 includes a branching path 85, an air outlet 82,
a suction fan 83 as an air generating unit 54.
[0131] Since other members have the same configuration as in the
embodiment described above, the same reference numerals are given
thereto and the explanation thereof will not be repeated.
[0132] Among these, the branching path 85 is provided so as to
branch off from the main line of a flow passage 86 within the range
where the opening portion 58 in the middle of an air guiding
portion 84 extends in the feeding direction Y same as the
above-described embodiment. In addition, the branching path 85 has
an air-opening valve 59b same as the above-described embodiment.
One feature that is different from the above-described embodiment
is that the downstream side of the air flowing direction in the
branching path 85 is connected to an air outlet 82. Different from
the blowing fan 55 (FIG. 2 to FIG. 5) of the air inlet 52 in the
above-described embodiment, a suction fan 83 is provide in the air
outlet 82 in the other embodiment 1.
[0133] In this case, the same action and effect can be obtained as
in the above-described embodiment by the control section 70 that
opens and closes the air-opening valve 59b in accordance with the
position of the tailing end P1b of the sheet P1. Specifically, by
opening and closing the air-opening valve 59b, the flow amount and
flow rate of the air in the vicinity of the third position (S3 (see
FIG. 3)) can be reduced. As a result, it is possible to reduce the
problem that the hot air flutters the tailing end P1b of the sheet
P1.
[0134] It is needless to say that the position of the branching
point 59a in the feeding direction Y is determined based on the
relationship between the force (suction force of a suction unit in
a suction belt mechanism, tension and weight of a sheet, and the
like) with which the tailing end P1b of the sheet P1 keeps its
positioning in the position in the direction of axis Z and the
force with which the suction fan 83 separates the tailing end P1b
of the sheet P1 from the supporters 22 and 23 supporting the sheet
P1, and the shape of the air guiding portion 84.
Other embodiment 2
[0135] FIG. 8 to FIG. 12 are side views schematically showing the
operation of the hot air unit according to other embodiment 2.
Among these, FIG. 8 shows a state where the leading end of a sheet
is positioned within the range where the opening portion extends in
the feeding direction. FIG. 9 shows a state where the tailing end
of the sheet reaches the position of a first branching point in the
feeding direction. Furthermore, FIG. 10 shows a state where the
tailing end of the sheet reaches the position of a second branching
point in the feeding direction. FIG. 11 shows a state where the
tailing end of the sheet reaches the position of a fourth position
in the feeding direction. FIG. 12 shows a state where the tailing
end of the sheet reaches the position of the downstream end of the
opening portion in the feeding direction.
[0136] As shown in FIG. 8 to FIG. 12, the hot air unit 91 according
to the other embodiment 2 includes a first branching path 93 to a
fourth branching path 96, and a first valve 93b to a fourth valve
96b. Among these, the first branching path 93 to the fourth
branching path 96 branch off from the main line of a flow passage
97 within the range where the opening portion 58 in the middle of
an air guiding portion 92 extends in the feeding direction Y.
Further, the first branching path 93 to the fourth branching path
96 are arranged in series in the order of the first branching path
93, the second branching path 94, the third branching path 95 and
the fourth branching path 96 from the upstream side to the
downstream side in the feeding direction.
[0137] The first valve 93b is provided in the first branching path
93, the second valve 94b in the second branching path 94, the third
valve 95b in the third branching path 95, and the fourth valve 96b
in the fourth branching path 96. The first valve 93b to the fourth
valve 96b are provided so as to be opened and closed by the control
section 70.
[0138] In addition, as examples of the first valve 93b to the
fourth valve 96b, a so-called electromagnetic valve which is a
solenoid valve may be used in the same manner as the air-opening
valve 59b in the above-described embodiment.
[0139] In the other embodiment 2, the point on which the first
branching path 93 branches from the main line of the flow passage
97 within the range where the opening portion 58 in the middle of
the air guiding portion 92 extends in the feeding direction Y is
assumed to be a first branching point 93a. Similarly, the point on
which the second branching path 94 branches off from the main line
of the flow passage 97 in the air guiding portion 92 is assumed to
be a second branching point 94a, the point on which the third
branching path 95 branches off from the main line of the flow
passage 97 in the air guiding portion 92 is assumed to be a third
branching point 95a, and the point on which the fourth branching
path 96 branches off from the main line of the flow passage 97 in
the air guiding portion 92 is assumed to be a fourth branching
point 96a.
[0140] Features that are mainly different from the configuration of
the above-described embodiment is that there are a plurality of
branching paths and valves in the other embodiment 2, and the hot
air unit 91 is provided lengthily in the feeding direction Y.
[0141] Since other members have the same configuration as in the
above-described embodiment, the same reference numerals are given
thereto and the explanation thereof will not be repeated.
[0142] Next, the operation of the first valve 93b to the fourth
valve 96b in the hot air unit 91 according to the other embodiment
2 will be explained.
[0143] As shown in FIG. 8, the (preceding) sheet P1 as the first
sheet is fed into the hot air unit 91 by the suction belt mechanism
20 after recording was performed in the recording section 40. The
leading end side of the preceding sheet P1 advances to the range
where the opening portion 58 is provided in the feeding direction
Y. At this point, all of the first valve 93b to the fourth valve
96b are in a closed state. Accordingly, it is possible to bring the
hot air flowing through the main line into contact with the leading
end side of the sheet P1 efficiently via the opening portion 58 and
to promote the drying of ink on the sheet without making the hot
air branch off from the main line 97.
[0144] As shown in FIG. 9, when the suction belt mechanism 20 is
driven further from the state of FIG. 8, the preceding sheet P1 is
fed further to the downstream side in the feeding direction. When
the tailing end P1b of the preceding sheet P1 reaches the position
of the first branching point 93a in the feeding direction Y, the
control section 70 opens the first valve 93b. Accordingly, it is
possible to branch off part of the hot air flowing through the main
line to the first branching path 93. Moreover, it is possible to
reduce the flow amount and flow rate of the hot air toward the
downstream side of the first branching point 93a in the feeding
direction Y in comparison with the state where the first valve 93b
to the fourth valve 96b are all closed.
[0145] As a result, it is possible to reduce the problem that the
hot air flutters the tailing end P1b of the preceding sheet P1 when
it positioned in the vicinity of the first branching point 93a in
the feeding direction Y.
[0146] In addition, it is possible to promote the drying of the ink
because it is possible to bring a certain amount of the hot air
into contact with the tailing end side of the preceding sheet P1
via the opening portion 58.
[0147] It is preferable that the distance from the upstream end of
the opening portion 58 in the feeding direction to the position of
the first branching point 93a in the feeding direction Y be as
short as possible. The reason is because it is possible to reduce
the problem of the tailing end of the sheet fluttering over that
distance.
[0148] It is preferable that the upstream end of the opening
portion 58 in the feeding direction is provided at the same
position as the position of the first branching point 93a in the
feeding direction Y when sectional areas in the air guiding portion
92 are same in the upstream side of the first branching point 93a
in the air flowing direction.
[0149] As shown in FIG. 10, when the suction belt mechanism 20 is
driven further from the state of the FIG. 9, the preceding sheet P1
is fed further to the downstream side in the feeding direction. A
(succeeding) sheet P2 as a second sheet is fed to the downstream
side in the feeding direction and the leading end side of the
(succeeding) sheet P2 as the second sheet advances into the range
where the opening portion 58 is provided in the feeding direction
Y.
[0150] The distance L1 from the tailing end P1b of the preceding
sheet P1 to the leading end P2a of the succeeding sheet P2 is equal
to the distance L3 from the fourth branching point 96a in the
feeding direction Y to the downstream end 58a of the opening
portion 58 in the feeding direction as description below.
[0151] When the tailing end P1b of the preceding sheet P1 reaches
the position of the second branching point 94a in the feeding
direction Y, the control section 70 opens the second valve 94b and
closes the first valve 93b. Accordingly, part of the hot air
flowing through the main line can be branched off toward the second
branching path 94. Moreover, it is possible to reduce the flow
amount and flow rate of the hot air toward the downstream side of
the second branching point 94a in the feeding direction Y in
comparison with the state where the first valve 93b to the fourth
valve 96b are all closed.
[0152] As a result, it is possible to reduce the problem that the
hot air flutters the tailing end P1b of the preceding sheet P1 when
it is positioned in the vicinity of the second branching point 94a
in the feeding direction Y.
[0153] In addition, it is possible to promote the drying of the ink
because it is possible to bring a certain amount of the hot air
into contact with the tailing end side of the preceding sheet P1
via the opening portion 58.
[0154] Furthermore, it is possible to make the flow amount and flow
rate of the hot air in the upstream side of the second branching
point 94a in the feeding direction the same as the flow amount and
rate in the state where the first valve 93b to the fourth valve 96b
are all closed. Accordingly, it is possible to maintain the drying
efficiency for the leading end side of the succeeding sheet P2. In
other words, there is no problem that the promotion of the drying
of the ink on the succeeding sheet P2 in the upstream side of the
second branching point 94a in the feeding direction is affected
even when the second valve 94b is opened.
[0155] Then, when the suction belt mechanism 20 is driven further
from the state of FIG. 10, the preceding sheet P1 and the
succeeding sheet P2 are fed further to the downstream side in the
feeding direction. When the tailing end P1b of the preceding sheet
P1 reaches the position of the third branching point 95a in the
feeding direction Y, the control section 70 opens the third valve
95b and closes the second valve 94b. Accordingly, it is possible to
branch off part of the hot air flowing through the main line toward
the third branching path 95. In addition, it is possible to reduce
the flow amount and flow rate of the hot air toward the downstream
side of the third branching point 95a in the feeding direction Y in
comparison with the state where the first valve 93b to the fourth
valve 96b are all closed.
[0156] As a result, it is possible to reduce the problem that the
hot air flutters the tailing end P1b of the preceding sheet P1 when
it is positioned in the vicinity of the third branching point 95a
in the feeding direction Y in the same manner as when it is
positioned in the vicinity of the second branching point 94a
described above.
[0157] In addition, it is possible to promote the drying of the ink
because it is possible to bring a certain amount of the hot air
into contact with the tailing end side of the preceding sheet P1
via the opening portion 58.
[0158] Furthermore, it is possible to make the flow amount and flow
rate of the hot air in the upstream side of the third branching
point 95a in the feeding direction the same as the flow amount and
rate in the state where the first valve 93b to the fourth valve 96b
are all closed. Accordingly, it is possible to maintain the drying
efficiency for the leading end side of the succeeding sheet P2. In
other words, there is no problem that the promotion of the drying
of the ink on the succeeding sheet P2 in the upstream side of the
third branching point 95a in the feeding direction is affected even
when the third valve 95b is opened.
[0159] Then, when the suction belt mechanism 20 is driven further
as shown in FIG. 11, the preceding sheet P1 and the succeeding
sheet P2 are fed further to the downstream side in the feeding
direction. When the tailing end P1b of the preceding sheet P1
reaches the position of the fourth branching point 96a in the
feeding direction Y, the control section 70 opens the fourth valve
96b and closes the third valve 95b. Accordingly, it is possible to
branch off part of the hot air flowing through the main line toward
the fourth branching path 96. In addition, it is possible to reduce
the flow amount and flow rate of the hot air toward the downstream
side of the fourth branching point 96a in the feeding direction Y
in comparison with the state where the first valve 93b to the
fourth valve 96b are all closed.
[0160] As a result, it is possible to reduce the problem that the
hot air flutters the tailing end P1b of the preceding sheet P1 when
it is positioned in the vicinity of the fourth branching point 96a
in the feeding direction Y in the same manner as when it is
positioned in the vicinity of the second branching point 94a
described above.
[0161] In addition, it is possible to promote the drying of the ink
because it is possible to bring a certain amount of the hot air
into contact with the tailing end side of the preceding sheet P1
via the opening portion 58.
[0162] Furthermore, it is possible to make the flow amount and flow
rate of the hot air in the upstream side of the fourth branching
point 96a in the feeding direction the same as the flow amount and
rate in the state where the first valve 93b to the fourth valve 96b
are all closed. Accordingly, it is possible to maintain the drying
efficiency for the leading end side of the succeeding sheet P2. In
other words, there is no problem that the promotion of the drying
of the ink on the succeeding sheet P2 in the upstream side of the
fourth branching point 96a in the feeding direction is affected
even when the fourth valve 96b is opened.
[0163] As shown in FIG. 12, when the suction belt mechanism 20 is
driven further from the state of FIG. 11, the preceding sheet P1
and the succeeding sheet P2 are fed further to the downstream side
in the feeding direction. When the tailing end P1b of the preceding
sheet P1 reaches the position of the downstream end 58a of the
opening portion 58 in the feeding direction Y, the control section
70 closes the fourth valve 96b. This is because the tailing end P1b
of the preceding sheet P1 is positioned beyond the range where the
opening portion 58 extends in the feeding direction Y and there is
no problem that the hot air flutters the tailing end P1b of the
preceding sheet P1.
[0164] On the other hand, the leading end P2a of the succeeding
sheet P2 reaches the position of the fourth branching point 96a in
the feeding direction Y. This is because, as described above, the
distance L1 from the tailing end P1b of the preceding sheet P1 to
the leading end of the succeeding sheet is equal to the distance L3
from the fourth branching point 96a in the feeding direction Y to
the downstream end 58a of the opening portion 58 in the feeding
direction.
[0165] After that, when the suction belt mechanism 20 is driven
further, the preceding sheet P1 and the succeeding sheet P2 are fed
further to the downstream side in the feeding direction.
[0166] When the tailing end P2b of the succeeding sheet P2 (as a
second sheet) reaches the position of the first branching point 93a
in the feeding direction Y, the control section 70 opens the first
valve 93b in the same manner as when the tailing end P1b of the
preceding sheet P1 reaches the position of the first branching
point 93a.
[0167] Then, the second valve 94b, the third valve 95b, and the
fourth valve 96b are opened in this order and a valve which has
been opened adjacent to the upstream side of the feeding direction
is closed as the position of the tailing end P2b of the second
sheet P2 moves toward the downstream side in the feeding direction
in the same manner as when the tailing end P1b of the preceding
sheet P1 moves.
[0168] As a result, it is possible to reduce the problem that the
hot air flutters the tailing end P2b of the succeeding sheet P2 in
the same manner as the tailing end P1b of the preceding sheet
P1.
[0169] Furthermore, there is no problem that the promotion of the
drying of the ink for the leading end side of the succeeding sheet
P (a third sheet) is affected in the same manner as the leading end
side of the second sheet P2.
[0170] As described above, by providing valves, it is possible to
reduce the fluttering of the tailing end P1b (or P2b) of the sheet
P1 (or P2) that is positioned within the range where the opening
portion 58 extends in the feeding direction Y without adjusting the
intensity of the blowing fan 55. At the same time, it is possible
to maintain the drying efficiency for the leading end side of the
succeeding sheet P2. In other words, it is possible to reduce the
problem of the tailing end P1b of the preceding sheet P1 fluttering
without lowering the drying efficiency for the leading end side of
the succeeding sheet P2.
[0171] The respective number of the branching paths and valves in
the other embodiment 2 is assumed to be four, but the number is not
limited thereto.
[0172] In the other embodiment 2, a plurality of the first
branching path 93 to the fourth branching path 96 as a branching
path having the first valve 93b to the fourth valve 96b as an air
releasing valve are provided, a plurality of the first branching
point 93a to the fourth branching point 96a as a branching point on
which the first branching path 93 to the fourth branching path 96
branch off from the air guiding portion 92 are arranged in series
in the feeding direction Y. With respect to the first valve 93b to
the third valve 95b other than the fourth valve 96b corresponding
to the fourth branching point 96a, which is the furthest downstream
in the feeding direction among the first valve 93b to the fourth
valve 96b, the control section 70 opens the valve (for example, the
first valve 93b in case of the first branching point 93a)
corresponding to the branching point (for example, the first
branching point 93a) when the tailing end P1b of the sheet P1
reaches the position of one branching point (for example, the first
branching point 93a) in the feeding direction Y. Further, the
control section 70 opens the valve (for example, the second valve
94b) corresponding to another branching point (for example, the
second branching point 94a) and closes the valve (for example, the
first valve 93b) corresponding to the one branching point (for
example, the first branching point 93a) when the tailing end P1b of
the sheet P1 reaches the position of the another branching point
(for example, the second branching point 94a) adjacent to the
downstream side of the one branching point (for example, the first
branching point 93a) in the feeding direction Y.
[0173] Furthermore, with respect to the fourth valve 96b
corresponding to the fourth branching point 96a, which is the
furthest downstream in the feeding direction among the first valve
93b to the fourth valve 96b, the control section 70 opens the
fourth valve 96b corresponding to the fourth branching point 96a,
which is the furthest downstream in the feeding direction Y, when
the tailing end P1b of the sheet P1 reaches the position of the
fourth branching point 96a, which is the furthest downstream in the
feeding direction, and the control section 70 closes the fourth
valve 96b corresponding to the fourth branching point 96a, which is
the furthest downstream in the feeding direction, when the tailing
end P1b of the sheet P1 reaches the position of the downstream end
58a of the opening portion 58 in the feeding direction Y.
[0174] In the other embodiment 2, the number of the branching paths
is plural from the first branching path 93 to the fourth branching
path 96, and the distance L1 between the tailing end P1b of the
preceding sheet P1 and the leading end P2a of the succeeding sheet
P2 is equal to the distance L3 from the fourth branching point 96a,
which is the furthest downstream in the feeding direction Y, to the
downstream end 58a of the opening portion 58 in the feeding
direction.
[0175] The method of controlling the first valve 93b to the fourth
valve 96b as a plurality of air releasing valves in the hot air
unit 91 of the printer 1 according to the other embodiment 2
includes feeding the sheet P to the downstream side in the feeding
direction by the transport unit 10 (S12); recording by discharging
ink onto the sheet P from the recording heads 41 (S13); detecting
the position of the sheet P in the feeding direction Y by the
second sheet detecting sensor 33 as the position detecting unit 30
(S15); drying ink on the sheet using the hot air unit 91 by
bringing the air guided by the air guiding portion 92 into contact
with the sheet P via the opening portion 58, the hot air unit 91
including the air generating unit 54 that is provided on the
downstream side of the recording heads 41 in the feeding direction
and generates air, the air guiding portion 92 that guides the air
generated by the air generating unit 54 from the upstream side to
the downstream side in the feeding direction and forms the flow
passage 97, and the opening portion 58 that extends in the feeding
direction Y in the middle of the flow passage 97 of the air guiding
portion 92 so as to face the sheet P (S14); with respect to the
first valve 93b to the fourth valve 96b that are arranged in series
in this order in the feeding direction Y, branched off over the
range where the opening portion 58 which extends in the feeding
direction Y, and provided on a plurality of branching paths from
the first branching path 93 to the fourth branching path 96 that
branches and guides part of the air flowing from the upstream side
to the downstream side in the feeding direction in the air guiding
portion 92 of the hot air unit 91, opening the valve (for example,
the first valve 93b in case of the first branching point 93a)
corresponding to one branching point (for example, the first
branching point 93a) when the tailing end P1b of the sheet P1
reaches the position of the one branching point (for example, the
first branching point 93a) in the feeding direction Y, with respect
to the first valve 93b to the third valve 95b other than the fourth
valve 96b corresponding to the fourth branching point 96a, which is
the furthest downstream in the feeding direction among a plurality
of branching points from the first branching point 93a to the
fourth branching point 96a, on which the first branching path 93 to
the fourth branching path 96 branch off from the air guiding
portion 92 among the first valve 93b to the fourth valve 96b, and
opening the fourth valve 96b corresponding to the fourth branching
point 96a, which is the furthest downstream in the feeding
direction, when the tailing end P1b of the sheet P1 reaches the
position of the fourth branching point 96a, which is the furthest
downstream in the feeding direction Y, with respect to the fourth
valve 96b corresponding to the fourth branching point 96a, which is
the furthest downstream in the feeding direction among the first
valve 93b to the fourth valve 96b (corresponding to S18 in the
above-described embodiment); and closing the valve (for example,
the second valve 94b) corresponding to one branching point (for
example, the first branching point 93a) when the tailing end P1b of
the sheet P1 reaches the position of another branching point (for
example, the second branching point 94a) adjacent to the downstream
side of the one branching point (for example, the first branching
point 93a) in the feeding direction Y, with respect to the first
valve 93b to the third valve 95b other than the fourth valve 96b
corresponding to the fourth branching point 96a, which is the
furthest downstream in the feeding direction among the first valve
93b to the fourth valve 96b, and closing the fourth valve 96b
corresponding to the fourth branching point 96a, which is the
furthest downstream in the feeding direction, when the tailing end
P1b of the sheet P1 reaches the position of the downstream end 58a
of the opening portion 58 in the feeding direction Y, with respect
to the fourth valve 96b corresponding to the fourth branching point
96a, which is the furthest downstream in the feeding direction
among the first valve 93b to the fourth valve 96b (corresponding to
S20 in the above-described embodiment).
[0176] The invention is not limited to the above embodiments,
various modifications can be made not imparting from the spirit of
the claim of the invention, and those modifications are also
included within the scope of the invention.
* * * * *